Degree Type

Dissertation

Date of Award

2016

Degree Name

Doctor of Philosophy

Department

Mechanical Engineering

Major

Mechanical Engineering

First Advisor

Kenneth M. Bryden

Abstract

This thesis develops a novel resource sharing approach for solving inverse radiant enclosure problems based on distributed construction which is then extended to provide a new controls algorithm for complex energy systems. Specifically, the problem of determining the temperature distribution needed on the heater surfaces to achieve a desired design surface temperature profile is recast as a distributed construction problem. This algorithm creates computational agents and the distribution and redistribution of a shared resource (blocks) allows these computational agents to manipulate a shared environment. The sharing of blocks between agents enables them to achieve their desired local state, which in turn achieves the desired global state. Each agent uses the current state of their local environment and a simple set of rules to determine when to exchange blocks, each block representing a discrete unit of change. By gradually building up a solution, this algorithm can be applied to any situation where the output is specified but the required inputs are unclear. In this problem the shared resource is temperature, which is distributed among the various surfaces by computational agents moving blocks. The algorithm is demonstrated using the established two-dimensional inverse radiation enclosure problem. The temperature profile on the heater surfaces is adjusted to achieve a desired temperature profile on the design surfaces. The resource sharing algorithm was able to determine the needed temperatures on the heater surfaces to obtain the desired temperature distribution on the design surfaces in the nine cases examined. This resource sharing algorithm is then extended to two controls problems—a simple physical realization of the radiant enclosure problem and a fuel cell-gas turbine hybrid power system at the National Energy Technology Laboratory’s Hyper facility. In both cases, the controls problem was posed as resource sharing problem, which was solved by incrementally building a solution using distribution construction. The primary strength of the algorithm is the ability to control a system without detailed analysis or development of transfer functions. In the case of the physical realization of the radiant heater problem, the new controls algorithm performed as well as a PID controller without the detailed system knowledge required to setup and tune a PID controller. In the case of the Hyper system, the controls algorithm performed as well as a MIMO controller. Future work will focus on extending the algorithm for load following applications in complex hybrid power systems, which typically require a large number of configurations at different power levels.

DOI

https://doi.org/10.31274/etd-180810-5682

Copyright Owner

Peter Samuel Broen Finzell

Language

en

File Format

application/pdf

File Size

206 pages

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